why doesnt he want to separate?
you said he complains about your relationship?
what is in it for him to stay together?
he seems to want the control?
what sort of angry behaviour?
he is threatening you? why? why doesnt he put dcs first?
in an ideal world, you would both agree to separate, as relationship is over, tell dcs together and point out you both still love themn...not blame one or the other...
fwiw, my ex also said he would never separate - in the end i had to leave the joint owned home with the dcs and rent elsewhere.
you cannot be held to ransom like this - you do have a choice not to continue to live with an angry man...